Apparatus for production of bellows tubing



Jully 5, 1932. w. B. CLIFFORD PPARATUS FOR PRODUCTION OF BELLOWS TUBING Filed Aug. 13, 1928 Y c Gmmwmww Patented July 5, 1932 UNITED STATES PATENT oFFicE ALTERB. CLIFFORD, OFCAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO CLIFFORD MAN U- APPARATUS FOR PRODUCTION 0F BELLOWS TUBING` Application med August 13, 1928. Serial No. 299,163.

The present invention relates to improvements in apparatus for production of bellows tubing, and more particularly to the type of machine disclosed in my copending application led of even date herewith Serial No. 299,164.

In this type of machine the bellows folds are formed through the employment of an internal fluid pressure in conjunction with a series of collapsible dies which causethe bulging of the tube in a predetermined manner as the tube contracts and the dies move toward one another. During the bulging operation, a substantial fluid pressure is maintained interiorly of the tube. This is accomplished by maintaining an end fitting mounted upon one end of the tube in sealing engagement with a fluid pressure head, the end fitting having a suitable liquid passage forl the maintenance of the desired pressure.l

The object of the present invention is to provide improvedfand adequate mechanism Y for engaging and sealing the open end of a tube without the employment of an end fitting, the mechanism operating automatically without manual intervention to hermetically seal the vend of the tube to the fluid pressure supply.

With this and other objects in view, the various 'features of the invention consist in certain novel features of construction, combinations and arrangements of parts hereinafter described and claimed, the advantages of which will be obvious to those skilled in the art from the following description.

In the accompanying drawing illustrating the preferred form of the invention,-

Fig. l represents a plan view partly in section of the improved `clutch mechanism for sealing the open end of the tube, together with the complementary dies cooperating therewith; Fig. 2 is an enlarged sectional view of the clutch mechanism;

Fig. 3 isl an end View of the clutch; and

Fig. 4 represents a slightly modied form of construction'.

It will be obvious to those skilled in the art that the internal fluid pressure employed during the formation of bellows folds is substantial and may amount to several hundred .is not only exerted radially of the tube, tending to expand between the dies, but is in additlon exerted axially due to the thrust against the closed end. The clutch mechanism, therefore, in order to be satisfactory in its operation, must not only hermetically seal the open end of the tube to the source of fluid pressure, but in addition must be capable of locking the tube in a fixed and predetermined position with relation to the fluid pressure head against the axial thrust tending to withdraw the tube therefrom. Any slight withdrawal of the tube during the formation of the bellows folds, even though it does not destroy the seal between the tube and the fluid pressure head, will nevertheless interfere with the uniformity of the operation and tend to cause the formation of a larger fold adjacent the fluid pressure head, due to the withdrawal of the material. y

As shown in the illustrated embodiment of the invention, the machine is provided .with a uid pressure head 10 cooperating with the usual partible die assembly, having a partible .end die 12 and intermediate dies 14. After the tube to be formed, indicated at 16, has beeen mounted within the dies and the latter locked thereabout, the fluid pressure head l0 together with the ram 18 are moved into engagementr with opposite ends of the tube 16, all as fully described in the application referred to. In the present mechanism this relative movement of the fluid pressure head and the die assembly, with the-` tube llocked therein, is relied upon to close the clutch in sealing engagement with the open end of the tube. To this end the lluid pressure head is provided with an elongated tubular sleeve 20, having at its end adjacent the die assembly a conical face 22 which is adapted tobe engaged by a series of similarly inclined faces 24 formed upon clutch members 26. Each of the clutch members 26 is mounted upon the end of a relatively long arm 28 extending integrally fromra hub 30. The inner engaging face 32 of each clutch member is comparatively narrow, and forms a portion of a cylindrical surface, the combined action of the four clutch members serving to grip a tube uniformly about its exterior. Positioned within the clutch members, which are uniformly disposed thereabout, is a complementary clutch tube 34 having a cylindrical outer surface,

fitting the interior surface of the tube\to be clutched. This complementary clutch tube extends throughout the length of the clutch arms, and is threadedly connected at 38 with the hub 30. In addition, the clutch tube 34 has an enlarged collar 40 at the rear end. fitting closely within the bore of the sleeve and engaging a series of yieldin packing members 42 between the collar and the hub to seal the space between the movabletive longitudinal movement of the clutch assembly within the sleeve 20. The extent of this movement is limited by a set-screw 44 mounted in the side of the hub 30 and having its end projectin into a slot 46 formed in the sleeve 20. e partible end plate 12 cooperates with the series of-clutch members 26 to causl a longitudinal movement of these members together with the complementary clutch tube with respect to the sleeve 20, and by virtue of such a movement to cause an engagement of the tapered faces 22 and 24 to move the inner faces 32 of the clutch members into sealing engagement with the tube surrounding the member 34. As indicated more particularly in the drawing, the die plate is formed as a separate piece 50, bolted to the end member 12 and having a portion 52 adapted to forman end bellows fold, and a cylindrical recess 54 engaging with reduced annular shoulders 56 on the clutch members to cause the inner faces of the portion 52 to contact with the end faces of the clutch plates when in operative position, and form a continuous surface in en gement with the outer wall of the tube. y virtue of this construction, the first fold of the bellows is formed beyond the' portion 52, and no opportunity exists for b'ulging of the tube between the ends of the clutch members 26 and the portion 52 Vwhich might interfere with withdrawal of the tube after formation of the bellows. As will be evident from the drawing, the cooperating tapered faces 22 and 24 are cut away to provide a minimum of' surface in frictional engagement, and facilitate disengagement of the clutch faces at the completion of the operation. It will furthermore be evident that the outer suri face of the tube 16 is clutched by the faces 32 in a comparatively narrow annular ring, thus permittxnga comparatively great pressure to be upon a relatively small area.

This not only insures a hermetic'sealing of uthe tube 16 to the clutch member 34, irrespective of variations in the thickness or dimensions of the tube longitudinally, but insures a clutching engagement of sufficient amount to prevent Withdrawal of the open end of the tube 16 from the clutch tube 34 when the internal Huid pressure is applied. f

As shown in Fig. 4, the inner surface of the tube instead of being clutched directly to the clutch tube 34, is clamped upon a cylindrical collar or bushin 60 which is mounted upon the reduced en 62 of the clutch'tube 34. The collar is held in place by a cap screw 66 threadedly engaged with the end of the clutch tube at 68. The clutch members are offset suiciently to surround the slight enlargement caused by the collar, and clutch the open end of the tube to the collar rather than the clutch tube 34. The operation of the two constructions is identical. Employment of a removable collar or bushing permits utilization of thel same clutch assembly for slightly varying sizes of tubes where the variation does not exceed perhaps a few thousandths of anv inch, without necessity for substituting a new clutch assembly.

As will be evident, fluid pressure is introduced into the tube through a passage 70 formed in the head and communicating with a longitudinal paage 72 extending through the interior of the clutch tube.

In the foregoing construction, the initial movement of the Huid pressure head as a whole toward the die assembly causes the extended end of the clutch tube to enter the open end of a tube 16 mounted in the die assembl Thereafter, engagement of the end die w1th the outer faces of the clutch members causes longitudinal movement of these members together with the clutch tube with relation to the sleeve 20. This longitudinal movement in turn exerts a gripping action of the clutch members upon the exterior of the tube 16 through engagement of the complementary tapered faces, further longitudinal movement then being resisted. Thereafter, the open end of the tube 16 is firmly locked and sealed to the extended end of the clutch tube, and the desired iiuid pressure may be introduced. During the formation of the bellows, no relative movement of the end plate 12 and clutch members occurs, the ram 18 moving toward the end plate and' clutch assembl as the tube is contracted. Upon completion of the operation, withdrawal of the ram 18 and fluid pressure head 10 releases the open end of the tube which may be thereafter removed from the dies.

It will be evident to those skilled in the art that inasmuch as one end of the tube 16 is engaged and supported by the ram 18, any ten ency to move the tube longitudinally with relation to the dies upon entrance of the clutch member 34 is posltively resisted.

lil)

Furthermore, during the actual formation of the bellows, the tube is gripped withsufiicient rigidity between the opposed clutch members to prevent withdrawal by virtue of the internal pressure. Under certain circumstances it may be desirable to enhance this gripping action by leaving the clam ing surface of the member 34 slightly rough)- ened, this roughening of the surface being on the order of such a roughening as would be caused by the tube marks ordinarily left after the turning down of the surface.

What is claimed is:

1. Apparatus for the production of bellows tubing comprising a die assembly adapted to support a tube therein, a sleeve movable with relation to the die assembly, a clutch assembly supported Within the sleeve and normally moving therewith, the clutch assembly comprising cooperating members engaging and clamping the open end of the tube interiorly and exteriorly and normally extending beyond the sleeve to be engaged and operated uponpmovement of the sleeve toward the die assembly, and means for automatically operating the clutch assembly upon engagement and continued movement of the sleeve.

2. Apparatus for the production of bellows tubing comprising a die assembly and a sleeve having capacity for relative movement lengthwise of a tube mounted within the die assembly, an inner clutch member having a circular tube engaging surface,'out er clutch members cooperating therewith, the inner and outer members having capacity for a unitary movement with relation to the sleeve, means for normally maintaining the inner and outer clutch members in advanced position with relation to the sleeve for initial reception of a tube therein,l and means for moving the outer clutch members into clutching position upon the occurrence of a movement with relation to the sleeve due to contact with the die assembly.

3. Apparatus for the production of bellows tubing comprising a clutch member adapted to be received within the open end of a tube, a plurality of external clutch members designed to engage the tube exteriorly and clamp the tube to the internal clutch member, means for supporting the internal and external clutch members to move axially of the tube while maintaining a. predetermined relationship between the members,

means for imparting a clutching movement.

to the external members upon such axial movement, and a means designed to engage and move the external clutch members into clutching relation on a. relative longitudinal sleeve, means for normally maintaining the clutch assembly in advanced position, and means for relatively moving the inner and outer members into clutching position upon a rearward movement of the clutch assembly due to engagement with the die assembly.

5. Apparatus for the production of bellows tubing comprising an inner clutch member having a substantially cylindrical tube-engaging surface and provided with a fluid pressure passage formed therein, a die assembly, means for moving. the' inner clutch member toward the die assembly, and means for causing the end of a tube surrounding the cylindrical surface to be rigidly clamped thereto externally when the inner clutch member has reached a predetermined position relative to the'die assembly.

6. Apparatus for the production of bellows tubing comprising a die assembly, a fluid pressure head movable relative to the die assembly, inner and outer complementary tube clutching members carried by the head, means for normally maintaining the clutching members in an advanced position with relation to the head, and means for causing a clutching movement of the members when the latter engage with the die assembly and upon continued movement of the head.

7. Apparatus for the production of bellows tubing comprising an outer sleeve, a clutch engaging tube slidingly mounted in the sleeve and having its free end extending beyond the sleeve and adapted to enter the open end of the tube, a series of external clutch fingers surrounding the tube back of the free end and mounted to move therewith, connections between the sleeve and fingers for moving the fingers into clutching engagement with the tube upon a relative longitudinal movement of the fingers with respect to the sleeve, and means designed to engage with the fingers and cause such movement.

8. Apparatus for the production of bellows tubing comprising a sleeve having an outer conical end, a clutch tube sliding within the sleeve and extending therebeyond, a series of external clutch fingers connected to the tube to move therewith as a clutch assembly and surrounding the tube adjacent the outer end, tapered outer faces on the lingers designed to engage the conical outer face of the sleeve, means for yieldingly maintaining the clutch tube and ingers in an advanced position with relation to the sleeve to permit the open end of the tube to be freely received between the clutch members, and means for rearwardly moving the clutch assembly with relation to the sleeve to cause clutching engagement thereby.

9. Apparatus for the production of bellows tubing comprising an inner clutch member, a collar having a circular tube-engaging surface detachably mounted on the end of the member, means for retaining the collar in position, a series of external clutch fingers positioned-opposite the circular surface of the collar and desi ed to clutch a tube thereto, and means or moving the fingers into clutching position about the collar.

10. Apparatus for the production of bellows tubing comprising a cylindrical clutch member designed to enter the open end of a tube, a series of clutch fingers designed lto engage the tube exteriorly through a comparatively narrow annular portion to clamp the tube to the cylindrical surface, a die assembly, and cooperatingl means for moving the clutch fingers inwar y to clamping position upon engagement of the fingers with the die assembly.

11. Apparatus for production of bellows tubing comprising a cylindrical member having approximately the internal diameter of the tube to be engaged, and adapted to project therewithin, outer clutch fingers cooperating therewith and designed to engage the tube exteriorly through acomparatively narro`w annular portion to clamp the tube to the cylindrical member, a die assembly within which the tube is mounted, and means for automatically moving the outer clutch fingers into tube-clamping position upon a movement which causes the cylindrical member to be entered within the tube.

12. Apparatus for production of bellows tubing comprising a die assembly within which the tube is mounted, an inner clutch member having a diameter approximating the internal diameter of the tube and aligned therewith, outer clutch members cooperating with the inner member, and means for causing the outer clutch members to engage with the tube in clamping relationship upon a movement which enters the inner member witljfthe end of the tube.

'f-i Apparatus for production of bellows tubing comprising inner and louter clutch members vfixed against relative longitudinal movement but capable of relative movement toward and from one another to clutch a tube engaged therebetween, a die assembly within which a tube is mounted'in alignment with the clutch members, and means for automatically moving the clutch members into operative position upon a movement to project the inner clutch member within the tube.

WALTER B. CLIFFORD.'

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